18 ❙ WATT POULTRY USA
» AMERICAN PROTEINS WINS CLEAN WATER AWARD
to work in the rendering facility; nothing
goes to waste.
Capturing energy
It takes a lot of energy to thermally
treat and remove the water from the
2,700 tons per day of chicken byproduct meal and 1,500 tons per week each
or pet food-grade meal and fat that are
produced at Cuthbert. For instance,
the natural gas bill to run
the plant's five cooker lines
can run over $1 million per
month.
To reduce odor, greenhouse gas emissions and to
lower the natural gas bill,
the Cuthbert plant has covered its anaerobic lagoon
and collects and burns the
biogas produced in the lagoon in its boilers. When natural gas
prices were at their highest level, the
plant saved around $100,000 a month
by burning about 1.5 million cubic feet
per week of biogas.
Thermal energy is recaptured from
the rendering process in a number of
ways at the Cuthbert plant. Offals are
around 65 percent water, and thermal
energy is used to evaporate water out of
the byproducts. The water vapor is con-
densed out of the exhaust and treated
to remove nutrients. The condensate
is 130-140 F, and this water can be
put into either the aerobic or anaerobic
lagoon in the winter months to warm
the bacteria up. A higher temperature
in the aerobic lagoon improves nutrient removal, and a higher temperature
in the anaerobic lagoon increases the
biogas production.
Heat energy in the
exhaust gases from the
cooking process is used
Treated effluent is land applied on hay fields that produce nearly 90,000 bales of
hay per year.
to preheat raw materials
like biosolids or dissolved air flotation skimmings prior
to the fat removal process.
Oil and protein
Brandon Kyzar, division manager,
American Proteins, said some poultry
companies look at dissolved air flotation skimmings and biosolids as part of
wastewater and not as a byproduct.
Dissolved air flotation skimmings
are comprised of oil, water and protein,
but many poultry plants
pay to have the skimmings land applied.
When injected underground, the skimmings
and other wastewater
treatment biosolids
(sludge) serve as soil
amendments, but their
disposal is a net cost to
the processor.
American Proteins
prefers to call items
like dissolved air flot at ion sk i m m i ngs
Trailers are washed out in the inside, and then the entire truck and "supplemental protein
trailer are washed before leaving the facility to help control odor.
nutrient," according to
Chris Jones, American Proteins environmental manager.
The Cuthbert plant has $10 million
worth of equipment which allows it
to remove water from supplemental
protein nutrient and separate out the
fat, leaving a high-protein feed ingredient. High fat prices have driven the
economics of processing supplemental
protein nutrient, and the Cuthbert facility now receives supplemental protein
nutrient from several plants, including processing the nutrient generated
on site.
Jones said that pet food companies
don't want any processed dissolved air
flotation skimmings or supplemental
protein nutrient in the ingredients they
buy. Cuthbert can process supplemental protein nutrient without impacting
their pet food products.
When fat prices were lower and
natural gas prices were higher, the
Cuthbert plant used reclaimed fat in
its boilers. Now that natural gas prices
are lower, the fat can be sold for use in
animal feeds or for making biodiesel.
Water reuse
The Cuthbert facility processes seven
days per week and there are more than
18,000 gallons per minute of recycled water
flowing though the plant at any given time.
The water is used to control temperatures
and collapse vapors on the cookers and
feather condensers.
The recycled water is also used in the
company's conditioning building, which
lowers the temperature of the plant operating air before it enters the biofilters. The
majority of the plant wash down water is
recycled water, and the water sprayed on
the biofilter media to maintain the correct
moistures is recycled water. Recycled water
is used to wash out all of the trailers on the
inside after dumping their load, and then
the whole truck and trailer are washed
again before they leave the plant.
"If the truck is clean it won't smell as
www.WATTAgNet.com ❙ June 2012

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